Two more wins and he will become the eighth male player to complete the so-called Sunshine Double. The last person to do so was Novak Djokovic in 2016 – his fourth.

With both players on top of their game, the first set was a tight affair, but it yielded no break points until game 12 when Raonic pounced to clinch the opener at the first attempt.

The next set followed a similar pattern, with just one chance being offered up by del Potro in game six.

But it was a different story in the tie-breaker as the Argentine raced into a 5-0 lead that gave Raonic no way back.

Amazingly, the third set began with four successive break before things returned to normal, before once again the world number six turned up the heat in the tie-breaker to claim victory in a shade under three hours.